Ring binder



FIG. 1 is a front perspective view;

FIG. 2 is a top view;

FIG. 3 is a side view;

FIG. 4 is a front view;

FIG. 5 is an other side view;

FIG. 6 is a bottom view; and,

FIG. 7 is a rear view. 

The ornamental design for a ring binder, as shown. 